T-cell lymphocytic leukaemia and lymphoma in a horse (abstract)

A 10-year-old Thoroughbred gelding showed rapid weight loss over about 1 week. Clinically, it had increased respiration and heart rates, dark red mucous membranes with petechial haemorrhages, and a bilateral keratitis. Routine haematological examination showed a lymphocytosis with increased numbers of small hyperchromatic lymphocytes in circulation, but no anaemia. On necropsy, many enlarged abdominal lymph nodes were seen and there was a large amount of fluid in the peritoneal cavity and pericardial sac. Histopathologically, small lymphocytes in- filtrated most tissues including the bone marrow, lymph nodes, liver, gastrointestinal tract and cornea. These were identified as T-lymphocytes by the use of immunohistochemistry and CD3 (positive), CD20 (negative) and CD 79a (negative) markers. A T-cell lymphocytic leukaemia and multi-centric lymphoma with generalised tissue infiltration were therefore diagnosed.

The effects of transdermal nicotine on inspection time

RATIONALE

The acute administration of nicotine via a cigarette has been demonstrated to enhance inspection time (IT), a measure of rapid visual information processing, while the nicotinic antagonist mecamylamine impairs IT. However, as transdermal nicotine patches provide a slow delivery of nicotine, it is unclear if they produce similar effects to nicotine administered by more rapid methods.

OBJECTIVES

To examine the effects of transdermal nicotine on inspection time.

METHODS

Ten moderate smokers were administered nicotine (21 mg/day) or placebo via a transdermal patch in a randomized, double-blind, repeated measures design. Subjects were administered the IT task at baseline, then 1, 3, and 6 h subsequent to patch application.

RESULTS

The change in IT from baseline was significantly different in the nicotine condition, relative to placebo, at 3 h but not 1 or 6 h.

CONCLUSIONS

The findings suggest that nicotine administered via transdermal patches improves IT, but this improvement may be subject to tolerance. Data from previous studies on tolerance to the cognitive effects of nicotine have been inconclusive. However, the slow delivery of nicotine from patches may be more likely to produce such effects.

Evidence of an early information processing speed deficit in unipolar major depression

BACKGROUND

Slowing of the speed of information processing has been reported in geriatric depression, but it is not clear if the impairment is present in younger patients, if motor retardation is responsible, or if antidepressant medications play a role.

METHOD

Twenty unmedicated unipolar depressed inpatients were compared with 19 medicated depressed in-patients and 20 age-, sex- and verbal IQ-matched controls on inspection time (IT), a measure of speed of information processing that does not require a speeded motor response. We also examined the relationship between IT and current mood and length of depressive illness.

RESULTS

Unmedicated depressed patients showed slowing of information processing speed when compared to both medicated depressed patients and controls. The latter two groups were not significantly different from each other. Slowing of IT was not associated with current mood, but was negatively correlated with length of illness since first episode. No differences in IT were found between patients receiving medication with anticholinergic effects and patients receiving medication with no anticholinergic effects.

CONCLUSIONS

The findings indicate that unipolar depression is associated with a slowing of speed of information processing in younger patients who have not received antidepressant medication. This does not appear to be a result of motor slowing.

Behavioral changes in Huntington Disease

OBJECTIVES

This study aimed to gain a better understanding of behavioral abnormalities in Huntington disease (HD) and to develop a method for reliably assessing these changes.

BACKGROUND

Behavioral changes are a central feature of HD and often cause considerable distress and difficulty to patients and their relatives. However, they have received little attention from research despite their prevalence and clinical significance.

METHODS

One hundred thirty-four patients with HD were assessed using the Problem Behaviors Assessment for Huntington Disease (PBA-HD), an instrument for rating the presence, severity and frequency of behavioral abnormalities in HD.

RESULTS

The findings confirm that behavioral problems are common among patients with HD. The most common symptoms were loss of energy and initiative, poor perseverance and quality of work, impaired judgment, poor self-care and emotional blunting. Affective symptoms such as depression, anxiety and irritability occurred in around half the patients studied. Psychotic symptoms (hallucinations and delusions) were rarely reported. Factor analysis distinguished three clusters of behavioral symptoms, which were interpreted respectively as reflecting Apathy, Depression and Irritability. The 'Apathy' factor was highly correlated with duration of illness, whereas no such relationship was observed for the 'Depression' and 'Irritability' factors.

CONCLUSIONS

The results suggest that certain behavioral changes are fundamental to the progression of HD, whereas others have a more complex relationship to the disease process. The findings have implications for the choice of behavioral measures used to evaluate efficacy of therapeutic interventions.

A human gastric cancer cell line possesses a functional receptor for gastrin-releasing peptide

Bombesin (BBS) exhibits diverse biological functions including those of neurotransmitter, regulator of gastrointestinal hormone release, and mitogen. Gastrin-releasing peptide (GRP, the mammalian equivalent of BBS) is found in mucosal cells of the gastric fundus and antrum. We determined whether a human gastric cancer cell line (SIIA) expresses a functional GRP-receptor (GRP-R). BBS increased intracellular calcium ([Ca2+]i), and a specific GRP-R antagonist, ([D-Phe6, Des-Met14]-BBS (6-14)-ethylamide), blocked BBS-induced increase in [Ca2+]i. SIIA cells possess GRP-R mRNA by reverse transcriptase-PCR. Furthermore, these cells possess an 80-kDa cell surface protein that specifically binds BBS with two high-binding affinities (Kd1 = 0.6 nM, Kd2 = 6.7 nM). These findings indicate that SIIA cells possess a GRP-R that is capable of physiological signal transduction, though the cellular response remains unknown.

The effects of nicotine on the 13 Hz steady-state visually evoked potential

OBJECTIVES

The high alpha/low beta range of the spontaneous EEG appears to be particularly sensitive to the effects of nicotine. The present study examined the acute effects of nicotine on the topography of the 13 Hz steady-state visually evoked potential (SSVEP).

METHODS

Thirteen moderate smokers participated in a repeated-measures design. The amplitude and latency of the SSVEP elicited by an unstructured sinusoidal 13 Hz flicker following a <0. 05 mg nicotine cigarette were compared to those following a 0.8 mg nicotine cigarette.

RESULTS

The nicotine condition was associated with an increase in the amplitude of the SSVEP, when compared to the placebo condition, and this increase was greatest in central and right parietal regions. The latency of the SSVEP was reduced in the nicotine condition in bilateral frontal and right parietal regions.

CONCLUSIONS

These results are similar to the effects of nicotine seen in studies examining spontaneous EEG, and are consistent with other studies indicating that the 13 Hz SSVEP indexes brain electrical activity in the high alpha/low beta range. The findings are discussed in terms of possible functional significance of nicotine-induced cortical activation in this frequency range.

Increased small bowel epithelial turnover in interleukin-1 receptor knockout mice

OBJECTIVE

To determine whether interleukin-1 (IL-1) affects the cellular homeostasis of small bowel mucosa, the authors studied apoptosis and proliferation in small bowel epithelium in two groups of C57 mice: an IL-1 receptor knockout group, and a control wild-type group.

SUMMARY BACKGROUND DATA

Gut mucosal integrity is maintained by a balance of cell proliferation and cell death. Recent reports suggest that IL-1, a proinflammatory cytokine, increases cell death by apoptosis in some epithelial cells.

METHODS

Twenty-four male C57BL6 IL-1 receptor (type I) knockout mice were killed, and small bowel was removed for study. Twenty-four wild-type mice (C57-BL6) served as controls. Body weights, bowel length, and mucosal morphology were examined for phenotypic differences. Apoptosis was quantified by terminal deoxyuridine nick-end labeling (TUNEL) immunohistochemical staining and cellular proliferation by proliferation cell nuclear antigen staining. Whole mucosal protein was analyzed for nuclear factor-kappaB expression. Groups were analyzed by t test.

RESULTS

The absence of IL-1 type I receptor in knockout mice was verified by reverse transcriptase-polymerase chain reaction. IL-1 receptor null mice were larger than wild-type controls, with a longer small bowel; however, the index of small bowel length to total body weight did not differ between groups. The percentage of apoptotic cells was higher in IL-1 receptor null mice than in wild-type mice; the proliferation index also increased. Mucosal height and other measures of mucosal morphology were not different. Genotypic absence of IL-1 receptors was associated with decreased expression of nuclear factor-kappaB in whole mucosal protein extracts.

CONCLUSIONS

Both apoptosis and proliferation increased in gut epithelial cells of mice without IL-1 receptors, suggesting increased cell turnover with no change in net balance. This model represents an opportunity to examine potential mechanisms of gut epithelial turnover in vivo, under both normal conditions and in conditions of mucosal proliferation and atrophy.

Effects of the nicotinic antagonist mecamylamine on inspection time

RATIONALE

Several lines of evidence suggest that nicotinic acetylcholine receptors (nAchRs) are involved in speed of information processing, and inspection time appears to be particularly sensitive to nicotinic manipulation.

OBJECTIVE

The present study sought to examine the effects of the nAchR antagonist mecamylamine on inspection time. Furthermore, the extent to which the anticholinesterase donepezil would reverse the effects of mecamylamine on inspection time was also examined.

METHODS

A double-blind, repeated measures design was employed. Subjects (n = 6) received placebo, mecamylamine (20 mg PO) or mecamylamine (20 mg PO) and donepezil (5 mg PO). Inspection time and physiological measures were then assessed.

RESULTS

The mecamylamine condition and the mecamylamine and donepezil condition were associated with an increase in heart rate, when compared to the placebo condition. There was a significant slowing of inspection time in the mecamylamine condition; compared to placebo, which was partly reversed by donepezil.

CONCLUSIONS

The slowing of inspection time following mecamylamine is consistent with the role of nAchRs in speed of information processing, and add to the evidence that IT may in part index nAchR system integrity.

[The long-term perfusion system on amylase release from dispersed acinar cells--comparative study with direct incubation techinique and residual stimulation]

We have modified the perfused guinea pig pancreatic acini system in order to obtain reproducible results in repeated secretagogue stimulation. No signs of tachyphylaxis were observed when cholecystokinin-8 (CCK-8) was administered as short pulse for 5 minutes and the interval between administrations were kept more than 90 minutes. Maximal amylase response was obtained at 10(-8) M of CCK-8 and a supra-maximal significant inhibition on amylase release was observed with higher doses of CCK-8. Twenty minutes stimulation with 10(-8) M of CCK-8 showed a biphasic response; while, 5 minutes stimulation showed a mono-phasic pattern. The results suggest that amylase response was highly influenced not only by the concentration of the secretagogue but also the duration of the stimulation in this perfusion system. The mechanism of this phenomenon may be comprehensive by the double-ligand-complex theory based on low and high affinity site on cell surface receptors.

Gut epithelial apoptosis after severe burn: effects of gut hypoperfusion

BACKGROUND

Severe cutaneous burn causes transient mesenteric vasoconstriction and altered gut mucosal integrity. We recently showed that burn also increases gut epithelial cell death by apoptosis. The goal of this study was to determine whether changes in gut perfusion after burn contribute to burn-associated gut apoptosis.

STUDY DESIGN

We first correlated superior mesenteric artery blood flow with measurement of gut perfusion at the tissue level by laser doppler in four nonburned rats before, during, and after arterial clamping to validate our measurements of gut perfusion. We then characterized gut perfusion sequentially over time after burn; gut perfusion was measured 3 cm from the ligament of Treitz before burn and hourly for 6 hours. A group of control rats underwent the exact same protocol without the burn to exclude effects of anesthesia and laparotomy on tissue perfusion (n = 4). We studied a third group of rats with hypoperfusion of the same duration and magnitude induced mechanically without burn (n = 7). Sections of the proximal gut from all three groups (control without burn, burn, and hypoperfusion without burn) were examined for epithelial apoptosis.

RESULTS

Linear regression analysis demonstrated a strong correlation between superior mesenteric artery blood flow and intestinal tissue perfusion measured by laser doppler under both low and high flow conditions (r = 0.85). Laser doppler measurements of gut perfusion after burn showed deceased gut perfusion that was maximal at 2 hours postburn (p < 0.05), and that persisted for 4 hours (p < 0.05). By 6 hours, gut perfusion returned to baseline. Apoptosis increased significantly in the burn group (2.11 +/- 0.17%) compared with control (0.52 +/- 0.2%) and the mechanically decreased perfusion group (0.51 +/- .03) (p < 0.001).

CONCLUSIONS

We conclude that burn-induced gut hypoperfusion is insufficient to cause burn-related increased gut epithelial apoptosis. We speculate that the signal for increased gut epithelial apoptosis is primarily related to proinflammatory mediators induced by the burn wound.

Hepatocyte growth factor modulates the hepatic acute-phase response in thermally injured rats

OBJECTIVE

Hepatocyte growth factor (HGF) has been shown to modulate the acute-phase response in vitro. The specific in vivo role of HGF in this multifactorial response, however, remains unknown. This study examines the effects of exogenous HGF on the acute-phase response in thermally injured rats.

DESIGN

Prospective, randomized, laboratory study.

SETTINGS

Shriners Hospital for Children and University of Texas Medical Branch laboratories.

SUBJECTS

Fifty-six male Sprague-Dawley rats (weight range, 300-325 g).

INTERVENTION

Animals received a 60% total body surface area third-degree scald burn and were randomly divided to receive either 400 microg/kg/day i.v. HGF or saline (control).

MEASUREMENTS AND MAIN RESULTS

Serum acute-phase proteins, cytokines, and insulin-like growth factor (IGF)-I concentrations, as well as liver weight, protein and triglyceride content, IGF-I concentrations, and cytokine gene expression were measured 1, 2, 5, or 7 days after burn. Serum albumin was increased on days 2, 5, and 7 after burn, and transferrin was increased on day 7 after burn in HGF-treated rats compared with controls (p<.05). HGF increased alpha2-macroglobulin concentrations on postburn days 2, 5, and 7 compared with controls (p<.05). Serum interleukin-6 and tumor necrosis factor-alpha were significantly higher within 2 days of burn in rats treated with HGF (p<.05). HGF increased the hepatic gene expression of tumor necrosis factor-alpha compared with controls (p<.05). Serum IGF-I decreased in rats receiving HGF 1, 2, and 5 days after burn, whereas liver IGF-I concentrations were higher on days 1 and 7 after burn compared with controls (p<.05). Hepatic protein concentrations were higher in the HGF group compared with controls on postburn days 1, 2, and 7, with a concomitant increase in total liver weight (p<.05). HGF exerted a strong mitogenic effect on hepatocytes 1 and 2 days after thermal injury compared with controls (p<.05).

CONCLUSIONS

These findings suggest that HGF modulates the acute-phase response in vivo after burn and causes changes in liver morphology.

Burn and starvation increase programmed cell death in small bowel epithelial cells

Maintenance of gut mucosal homeostasis depends on a balance between cell proliferation and cell death. Gut mucosal integrity is impaired after severe burn and during starvation. We determined the effect of burn, starvation, and the combination of both on small bowel epithelial apoptosis and proliferation. Fifty adult male Fischer 344 rats (260-300 g) received a 60% full-thickness scald burn and were randomly divided into fed and starved groups. Small intestine was taken at 12, 24, and 48 hr after injury. All animals in the 12-hr group were starved while recovering from anesthesia. Apoptosis was quantified by immunohistochemical staining (TUNEL) and mucosal proliferation was determined by bromodeoxyuridine (BrdU) incorporation. The apoptotic index was higher in burned rats compared to controls at 12 hr after burn; both these groups were starved (P < 0.05). At 24 and 48 hr after burn, apoptosis was highest in the starved groups, with no additional effects of burn (P < 0.05). Mucosal epithelial cell proliferation was not different between groups at any time point. In conclusion, burn and starvation both increase apoptosis in the small bowel mucosa; however, these effects are not additive. Apoptosis could be attenuated by enteral feeding, which delineates the importance of early enteral feeding initiation after injury to maintain mucosal integrity.

The effectiveness of individual versus group induction of depressed mood

This study is an investigation of the effectiveness of an individually administered mood induction procedure compared with an equivalent procedure administered to a group. Seventy-nine nondepressed individuals (25 men, 54 women) were randomly assigned to either a depressive or a neutral mood induction in an individual or a group setting. In each procedure, the mood induction involved the Velten self-statement procedure (E. Velten, 1968) enhanced by related mood music. Overall, both the individual and group induction procedures were effective in producing a depressed mood state, and their effectiveness was unrelated to social desirability or the sex of the participant. However, the group procedure was more vulnerable to individual differences in response, and its use in research on depression requires stringent criteria for mood change.

Automated homogeneous immunoassay for gentamicin on the dimension clinical chemistry system

BACKGROUND

Monitoring of the concentration of gentamicin in serum and plasma during therapy is widely recommended and practiced in hospitals. Our aim was to develop a homogeneous immunoassay based on particle-enhanced turbidimetric inhibition immunoassay technology to quantify gentamicin on the Dimension clinical chemistry system.

METHODS

Assay performance was assessed on each of the Dimension models in a 15-instrument interlaboratory comparison study. A split-sample comparison (n = 1171) was also performed between the gentamicin methods on the Dimension system and the Abbott TDx analyzer, using multiple reagent and calibrator lots on multiple instruments.

RESULTS

The Dimension method was linear to 25.1 micromol/L (12.0 microg/mL) with a detection limit of 0.63 micromol/L (0.3 microg/mL). Calibration was stable for 30 days. The within-run imprecision (CV) was <1.3%, and total imprecision ranged from 1.8% to 3.2% between 4.2 micromol/L (2.0 microg/mL) and 16.7 micromol/L (8.0 microg/mL) gentamicin. Linear regression analysis of the results on the Dimension method (DM) vs the Abbott TDx yielded the following equation: DM = 0.98TDx - 0.42; r = 0.987. Minimal interference was observed from structurally related compounds such as sagamicin, netilmicin, and sisomicin.

CONCLUSION

The monoclonal antibody used in this method has similar reactivities toward the individual gentamicin subspecies C1, C1a, and C2, thus providing analytical recovery not significantly dependent on relative subspecies concentrations.

Cutaneous burn increases apoptosis in the gut epithelium of mice

BACKGROUND

Gut mucosal homeostasis depends on a balance between cell proliferation and cell death. After cutaneous burn injury, gut mucosal weight has been shown to decrease. This decrease in weight was paradoxically associated with an increase in gut proliferative factors. For mucosal weight to decrease in the presence of increased proliferation, there must be an even greater increase in cell death. We postulate that cutaneous burn injury causes an increase in gut epithelial cell death primarily by apoptosis.

STUDY DESIGN

We produced a 30% full-thickness scald burn in the dorsum of anesthetized male C57BL6 mice and collected the proximal small bowel at 12, 24, 36, 48, and 60 hours after injury. Sham burned animals served as controls. Apoptosis and proliferation were measured by immunohistochemical assays (terminal deoxyuridine nick-end labeling for apoptosis and proliferative cell nuclear antigen assay for proliferation). Apoptosis was also measured by ELISA for cytoplasmic histone-associated DNA fragments. Mucosal height was determined on histologic sections. The two groups were compared at each time point using Wilcoxon two-sample test and t-test with Bonferroni's correction where appropriate.

RESULTS

The percentage of apoptotic cells (number of cells stained by terminal deoxyuridine nick-end labeling per 100 villus cells) was significantly higher at 12, 24, and 48 hours after injury. This increase was corroborated by an increase in the ELISA at 12 hours. Proliferation as measured by immunostaining for proliferative cell nuclear antigen significantly increased at 12, 24, 48, and 60 hours. Mucosal height as a gross measure of mucosal atrophy was not different between the groups.

CONCLUSIONS

We have shown an increase in apoptosis coupled with an increase in proliferation after a burn injury. These results imply an increase in cell turnover in the gut epithelial cells after a burn. Impaired bowel function has been demonstrated repeatedly after burn injury, and this increase in cell turnover may be related.

Bombesin stimulates in vitro growth of human breast cancer independent of estrogen receptors status

BACKGROUND

Approximately 180,000 women will be found to have breast cancer this year in the United States. Chemotherapy has limited success in advanced disease and the effect of tamoxifen appears to require a functional estrogen-receptor (ER). Our aim was to determine whether bombesin (BBS) regulates growth of human breast cancer cells.

METHODS

Estrogen-dependent (MCF-7), estrogen-responsive (ZR-75-1) and estrogen-independent (MDA-MB-231) human breast cancer cells were studied. Receptors were identified by cross-linking methods and radioligand binding assays; intracellular calcium ([Ca2+]i) was measured after BBS treatment to confirm functional status of the receptor; and the effect of BBS on cell growth was measured directly.

RESULTS

All three cell lines had a high affinity BBS receptor (Kd = 1-7 nM; molecular weight 75 kDa). BBS stimulated [Ca2+]i levels as well as cell growth in all three cell lines; the trophic effect was blocked by BBS receptor antagonists.

CONCLUSIONS

We conclude that BBS is trophic for human breast cancers independent of ER status, and that antagonism of the BBS receptor may be a useful target for hormonal therapy in ER-negative breast cancer.

Novel expression and regulation of gastrin gene in human ovarian cancer cell line, SW626

Gastrin-secreting tumors have been identified in ectopic locations including the ovary; the mechanisms regulating gastrin gene expression, its distribution, and signaling pathways in these ectopic tissues are not known. The purpose of our present study was to determine: (1) whether the gastrin gene and peptide could be detected in ovarian cancer cell lines, (2) if functional gastrin releasing peptide receptors (GRP-R) are present, and (3) whether gastrin gene expression is altered by GRP. Five ovarian cancer cell lines (SW626, OVCA 420, OVCA 429, OVCA 432, and OVCA 433) were analyzed. We identified gastrin gene and peptide expression in the SW626 cell line but not in the OVCA lines. SW626 cells express a functional GRP-R that is correctly coupled to the Ca2+ signaling pathway. Treatment of SW626 cells with bombesin, the amphibian equivalent of GRP, inhibited expression of the gastrin gene in a time- and dose-dependent fashion. The SW626 ovarian cancer cell line will provide a useful model to further define regulation and expression of both the gastrin gene and peptide in ectopic (nongastrointestinal) tissues.